


The Stars Which We Die Under

by duckydotducky



Category: Undertale (Video Game)
Genre: Alternate Universe - Reincarnation, Alternate Universe - Soulmates, Angst, Angst and Hurt/Comfort, Asexual Character, Big Brother Sans (Undertale), Character Death, Fluff, Fluff and Angst, Fluff and Hurt/Comfort, Implied/Referenced Character Death, Implied/Referenced Suicide, Nonbinary Character, Other, Reader Is Not Frisk (Undertale), Slow Burn, Younger Brother Papyrus (Undertale)
Language: English
Status: In-Progress
Published: 2020-07-05
Updated: 2020-07-05
Packaged: 2021-03-04 23:55:05
Rating: Teen And Up Audiences
Warnings: Major Character Death
Chapters: 1
Words: 490
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/25085005
Author URL: https://archiveofourown.org/users/duckydotducky/pseuds/duckydotducky
Summary: Monsters, who are in tune with their souls, know when their soulmates reach a certain age.A monster will only have a monster as another soulmate.Right?
Relationships: Alphys/Undyne (Undertale), Papyrus & Sans (Undertale), Papyrus & Undyne (Undertale), Sans (Undertale)/Reader
Comments: 5
Kudos: 49





	The Stars Which We Die Under

**Author's Note:**

> Hi! I wanted to get this posted before I went to bed for the night. War and Mander is on its last stretch and this will be my new project. Not all chapters will be this small.
> 
> Please note that there will be no sexual scenes in this fic. I'm not comfortable writing them. 
> 
> Also coming up for a soulmate au that spans generations without going pedo is harder than you think.

He first noticed the pull when he was 15. It was uncomfortable, but a pleasant type of uncomfortable. His soul pounded hard, and he could feel himself rattle with excitement. He grabbed his coat, ready to follow the pull of his soul to where it wanted to take him.

But just then, Papyrus let out a wail and started crying from the other room. Sans hesitated for a split second before putting his coat down. Papyrus came first. He could always go look for his soulmate another time.

“what’s up bud?” he asked, sitting down on the edge of the mattress that served as their bed. Papyrus looked up at him with tear filled eyes.

“I had a nighmare…” he said softly, all his usual loud excitement gone from his voice. Sans sighed and smiled. It was late and he had to work in the morning anyway. 

“well scoot over so i can chase them off with my snoring,” he said, giving Papyrus a gentle push. The babybones giggled and Sans slid in under the covers next to him. He wrapped his arms around his little brother and pulled the blankets up over their shoulders.

“Nigh Sans…” Papyrus muttered. Sans smiled and patted his head.

“night bro.”

Between raising Papyrus and trying to survive, Sans didn’t notice the time flying by. He always felt the tug in the back of his mind, reminding him that he had yet to find his soulmate. As time went on, the tug became less and less distracting. He found himself wrapped up in projects and jobs. He was distracted by friends and Papyrus’s antics. 

Days turned into weeks. Weeks turned into months. Months turned into years. Before he knew it, he was a full grown monster. His magic had stopped his body from growing and physically changing when he was around 26. The years kept adding on and if it wasn’t for Papyrus, he wouldn’t have even celebrated his birthday after a certain point. 

Everything was fine until one day when he was 98. It was sudden and it doubled him over on the floor. He fought back the urge to scream. His soul felt like it was being shredded apart and he was sure he was going to die. 

Papyrus rushed over to him, dropping the plate of food that he was bringing to Sans. “SANS? SANS?? ARE YOU OK??” Sans couldn’t hear him above the rush of pain coursing through his soul.

Then, almost as quickly as it started, it ended. Sans didn’t uncurl though, and laid on the floor. Tears flowed freely from his eyesockets as he sobbed. Papyrus kept trying to get his attention and ask him what was wrong, but Sans didn’t answer him, too caught up in the grief to say anything.

He knew what had happened. There was no denying it. He could feel it deep within the very core of his being. His soulmate was dead.


End file.
